Heating system



March 7, 1933. T E, MURRAY, JR ET AL 1,899,977

HEATING SYSTEM Mardi 7, 1933-` T. E. MURRAY, JR., ET AL 1,899,977

HEATlNG SYSTEM Filed Feb. 14, 1950 2 Sheets-Sheet IMI.

Patented Mar. 7, 1933 UNITED sTATEs PATENT ori-Ice THOMAS E. MURRAY, JR., OF BROOKLYN, NEW YORK, AND GEORGE H. PHELPS, OF

WAREHOUSE POINT, CONNECTICUT, ASSIGNORS, BY DIRECT AND MESNE ASSIGN- MENTS, TO 'METROPOLITAN ENGINEERING COMPANY, A CORPORATION OF NEW Yom:

HEATING SYSTEM Application ledebruary 14, 1930. Serial No. 428,265.

In the present system for heating large buildings by means of steam, 1t 1s customary to connect each radiator to two pipes, one a steam supply pipe and the other a return' From the return main the air is either vented to the atmosphere (in vapor systems) or pumped out (in vacuum pump systems) and the water is returned to the boiler.

It is obvious that the above described systems are expensive to install since two complete systems of piping (a supply line anda return line) are required throughout the building and since each radlator must be equipped with a valve and a return trap.

The present invention provldes a system which is simple and less expenslve to install and maintain and by which we can completely or largely eliminate the use of steam valves and traps, air valves and other accessories needed with prior systems.

The accompanying drawlngs illustrate an embodiment of the invention.

Fig. 1 is a diagrammatic elevation partly in vertical section of a complete system;

Figs. 2 and 3 are vertical sections of two fittings used on the vertical pipe for oo nnecting it -to the radiators;

Fig. 4 is a diagram in perspective of an encased radiator as used in the system.

In the case illustrated, a single steam main is `carried from the boiler to the top of the building (though more than one may be used if it is desired to sectionalize a very large building). This main is connected to feed into the tops of a series of vertical risers or down-takes runnin down through a number of floors of the uilding at points at which it is desired to have radiators. To

these risers are directly connected the radiators on the various floors one beneath the other. At the bottom end of each ofthese risers is placed a single return trap of large size and below this trap the Water and air are connected into a basement return line from which the air is allowed to escape or is expelled as in ordinary systems and the water is returned to the boiler.

There are no run-outs (short lengths of pipe with special fittings between the main and the radiators),` no valves and few return traps. There is a saving of labor on this account alone in installing such a system and a further saving of labor in installing the single and direct steam main in place of the usual more intricate system. There is also a large saving in the cost of material compared with the older systems.

A boiler 1 in the basement generates steam which is carried to the top of the system through a main 2 and distributed through lateral feeders 3 at the topto risers 4 which lead downward past the radiators in a vertical line of rooms; each radiator being designated as a whole by the numeral 5 and enclosed within a casing 6.

It is customary to feed about 20 radiators, that is 20 floors, from a given riser and thus sectionalize the building into vertical units of about 20 floors, though this is not necessary f, for any reason, it is found undesirable to o so. l

At the lower end of each riser the condensate passes through a steam trap 7 and a return line 8 to the boiler. An air vent 9 permits escape of the air from the line.

The riser 4 has interposed in its length two types of fittings 10 and 11 shown in detail in Figs. 2 and 3. The fittings 10 are continuously open and are to be used where the load, or demand for steam, on radiators at lower levels is sufiicient to ensure the operation hereinafter described. Such fittings will be used therefore for the radiators on the upper part of the riser, but not for the lowest radiator and preferably not for the last three or four.

For these the fitting 11 or some similarly operating arrangement should be used. The

fitting 11 may be used for all the radiators. but the fitting 10 is simpler and is preferred where it can be used.

Referring to Fig. 2, the steam, with the condensate of radiators on higher floors if any, enters the upper end 12 and flows partly through the upper lateral branch 13 into the radiator and partly through the constricti'ng nozzle 14. Any water entering the upper end fiows straight down through the nozzle. The steam entering the radiator at the upper connection travels through the same and expels air and water from the radiator directly into the lower branch 15. After the air is completely expelled, the tube or passage-way through the radiator is in full contact with steam throughout its length and is in readiness to operate at its full rated heating capacity. The steam and condensate from the radiator, therefore, join that from the nozzle 14 and pass out through the lower end 16. Steam having passed through the nozzle will not flow back through the branch 15 into the radiator for these reasons.

The pressure of steam at the entering end 12 is greater than that at the exit end 16 because of the friction produced by the constricted nozzle. The pressure in the branch 15 is less than that at the end 16 because of the injector or suction action of the jet of steam issuing from the nozzle into the larger pipe below. The pressure at the upper end therefore will be considerably more than in the lower branch 15, the diHerence being possibly about one-half to one and one-half ounces per square inch.

The dierence is sufficient to cause the steam to enter the radiator at the upper branch with sufficient force to expell the air and water at the lower branch. The radiator is continually purged of air and condensate by a flow of steam. n

Tn order that this fitting 10 shall operate as described, there must be a load, or demand for steam, at lower levels sufficient to induce a flow through the nozzle and substantial pressure differences at the points referred to. rTherefore it cannot be used for the lowest radiator nor where the demand for vsteam by radiators at lower levels is too little to ensure a steadily sufficient pressure difference to cause continual purging.

For these lower radiators a fitting 11, Fig. 3, is used. Steam and condensate enter at the upper end 17. The steam passes into the radiator through the lateral branch 18, out of the radiator through 19 and thence out of the lower end 20 of the fitting. The condensate accumulates until it fills a cup 21 suciently to submerge the end of the inner tube 22 and forms a trap which seals the litting against the direct passage of steam.

When a sufficient demand for steam by the radiators below causes a pressure drop as great as the water head in the trap, this will Laage?? cause the expulsion of the water from the trap and steam will flow directly through the fitting as well as through the radiator. Water will continue to collect in and to be ex elled from the trap as long as the demand elow is suiicient to require it. When this condition ceases, the flow of steam will be automatically sealed at the trap and the entire steam supply will pass through the radiator.

Thus the water head limits the difference between the pressures at the radiator inlet and outlet respectively to a predetermined maximum Value. When the pressure difference reaches such maximum value or tends to exceed it, the. steam passes directly through the trap.

This fitting will operate the lowest radiator to perfection and will operate best where the load below it is comparatively small, while the fitting 1() is best suited for opposite conditions.

The control of heat input to individual rooms is effected by stopping or controlling the flow of air past the radiator and into the room. Fig. 4 represents a radiator of the Murray type having a steam tube 23, 23a embraced between corrugated sheets which form vertical lues 24 and 25 open at top and bottom. In these flues the air is heated and a strong upward draft induced.

Various other styles of radiator may be used. The whole is carried in an enclosure indicated as a single. rectangular box having at the top a hinged lid 27 which can be shut down to close the tops of the dues and to prevent substantial escape of heated air, and a hinged plate 28 for opening or closing an air inlet at the bottom.

The upper damper will in most cases be sufficient alone to control the heat output of the radiator. llt prevents the egress of heated air from the cabinet very satisfactorily without the help of the lower damper 28.. Heated air being lighter rises to the top of the cabinet and cannot leave by the lower opening.

The lower damper 28 by itself will limit the output of the radiator to a certain degree, but not so com letely as the upper one alone. Even where t e bottom is closed, the top being open, heated air will flow up and out of the enclosure at some part of the opening while cool air flows down and into the enclosure at other locations. Usually the heated air rises near the centre and the cool air passes down at the ends and sides to the bottom and thence up through the centre as it is heated.

A single damper, therefore, placed at the egress opening will sufficiently regulate or prevent the operation of the radiator; while a single damper at the entrance is less efficient. Y

Various other styles of damper ma be used and various enclosures, either ins ated to cut off all heat or of metal which permits radiation of a certain quantity of heat without actual escape of heated air. The dampers may4 be set at intermediate positions to limit the flow of air as desired. As the flow of air is limited, so also is the quantity of steam condensed in the radiator. The radiator, however, is kept hot and ready to supply heat instantly when the damper or dampers are opened. At the same time the dampers on other iioors may be open to supply heat to the desired extent.

The special fittings may be dispensed with and a plain pipe riser used by providing special means for getting rid of the air, such as an air valve on each radiator. Steam would then enter the radiator through both upper and lower connections. This, however, introduces an opportunity for leakage and faulty operation into every radiator of the system and necessitates radiator enclosures which allow easy access to service the `air valves.

Murray convection radiators of two-pipe height are specially adapted to the system described, or of any multiple of two tubes, the fittings of course being of corresponding` height. The flue system with its strong draft of heated air makes the damper control specially eliective. The radiators, however, may be of various other types and materials and the fittings may be considerably changed in design.

The inlet 23 and the outlet 23a of the radiator are diagrammatically indicated in their proper relative positions for connection to the ttings, Figs. 2 and 3.

What we claim is'- 1. A steam heating system including in combination a vertical line of radiators of the convection type in which the greater portion of the heat is transmitted to air which is circulated over the heating surfaces, means for regulating separately the flow of air over each radiator and thereby the consumption of steam, a riser carrying the steam s upply and connected to the inlet and outlet respectively ofeach of said radiators, means in the riser between the inlet and outlet of each of the radiators for maintaining a higher pres- V sure of steam at the inlet of the radiator than at its outlet and means in the lower part of the riser for limiting the difference between the pressures at the inlet and the outlet respectively of each radiator to a predetermined maximum so that the required diern ential pressure is maintained for all the radiators in the line independently of any diferences in their consumption of steam.

2. A steam heating system including in combination a riser carrying the steam supply and a vertical line of radiators to which the riser is connected in succession, means in the riser between the inlet and outlet of each of the radiators for maintaining a higher pressure of steam at the inlet of the radiator than at its outlet and means in the lower part of the riser for limiting the difference between the pressures at the inlet and outlet respectively of each radiatorto a predetermined maximum so that the required differential pressure is maintained for all the radiators in the line independently of any differences in their consumption of steam.

3. The steam heating system of claim 2, the means for limiting the difference between the pressures at the inlet and outlet respectively of each radiator to a predetermined maximum consisting of a trap in the riser between the inlet and outlet ends of a radiator.

In witness vwhereof, we have hereunto signed our names.

THOMAS E. MURRAY, JR. GEORGE H. PHELPS. 

